Artificial foot(two-link)



J. G. CATRANIS ARTIFICIAL FOOT (Two LINK) 2 Sheets-Sheet l July 5, 1949.

Filed Dec. 11, 1947 `f /NVENTOR- .my 194, J. G. cATRANls 2,475,372

ARTIFICIAL FOOT (TWO LINK) Filed Dec. 1l, 1947 2 Sheets-Sheet 2 VIII/l L IN VEN TOR.'

Patented July 5, 1949 UNITED STATES PATENT OFFICE 2,475,372 ARTIFICIAL FOUT (TWO-LINK) John G. Catranis, Syracuse, N. Y. Application December 11, 1947, Serial No. 791,127

14 Claims.

This invention relates to artiiicial leg and foot structures, and has for its object a sectional foot structure, the sections of which are pivotally connected or articulated together, and have movement during the walking cycle against spring resistance, all so as to effect laterial flexion and progressive dorsiflexion.

More specifically, it has for its object a foot structure consisting of :an` upper tarsus section and a lower tarsus section hinged together by a forward and rearward extending pivotal or hinged joint, a metatarsal section consisting f right and left divisions hinged to the front end of the lower tarsus section, phalangesA sections consisting of right and left divisions hinged on a transverse axis to the front end of the metatarsal divisions, the upper tarsus having a rigid forward extension overhanging the metatarsal section, and spring means interposed between the metatarsal and phalanges sections and the rigid overhanging portion of the upper tarsus section to resist pivotal movements of the vrnetatarsal and the phalanges sections and divisions.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views. .A

Figure 1 is a side elevation of an articial foot structure and the contiguous portion of the leg structure embodying this invention.

Figure 2 is a plan view of parts seen in Figure l, part of the upper tarsus section being removed.

Figure 3 is a longitudinal sectional view of the foot structure and the contiguous portion of the leg structure.

Figures 4, 5, 6 and I are sectional views taken respectively on line 4-4, 5 5, 6--3 and 1-I, Figure 3.

The reference numeral I designates the upper tarsus section, 2 the lower tarsus section, 3 the metatarsal section, and 4 the phalanges section. 5 designates the contiguous portion of the leg structure.

The upper tarsus section I is formed with a recess 6 in its upper side, or is in the general form of a box, and is provided with depending spaced lugs 'I on its lower side which extend into a recess 8 in the lower tarsus section 2. It is pivoted or hinged to the lower tarsus section as by a forward and rearward extending pivot or spindle 9 extending through the lugs 1 into bearings Il), II, in the adjacent walls of the lower tarsus. The

upper tarsus section is also formed with a forward extending rigid portion I3 constituting the instep part of the foot structure, this overhanging the metatarsal section 3. The metatarsal section 3 is hinged or pivoted at its rear end at I4 to forwardly extending bearing lugs I5 at the front end of the lower tarsus section 2, this pivot extending transversely on a substantially horizontal axis. The metatarsal section 3 is here shown as formed with a bearing hub I5 extending transversely thereof and mounted on the pivot I4, there being a bushing I1 between the hub and the pivot I4. As seen in Figures 2 and 5, the metatarsal section consists of right and left divisions or links, each pivoted at its rear end at I4 to the front end of the lower tarsus section, and at I8 to one of the divisions of the phalanges section.

The phalanges section 4 is hinged at its rear end on a transverse axis at I8 to the front ends of the right and left divisions of the metatarsal section 3. As seen in Figures 1 and 6, the phalanges section 4 is composed of right and left divisions, or halves. There is a transverse pivot I8 for each division. As here shown, each division of the phalanges section is formed with a pair of upward extending bearing lugs I9 between which stop arms 2|) on the metatarsal section extend, the stop arms having bearings for the hinge pins IB which also extend through the bearing lugs I9.

The spring means for resisting the pivotal movement of the metatarsal and phalanges sections 3, 4, is here illustrated as a laminated leaf spring 2| having a saddle 22 at its rear end seated on the hub I6, the front end of the spring pressing on the phalanges section at 23, and the intermediate part of the spring being ulcrumed at 24 on the under side of the front end of the rigid extension I3 of the upper tarsus. As the phalanges section is composed of right and left divisions, see Figure 6, the front end of the spring 23 presses on a iiexible fibrous bridge 25 connecting the sections, as shown in Figure '7. The stop arms 20 are located to limit the flexing action of the phalanges divisions relative to the metatarsal section 3. Rubber bumpers 26 are interposed between the forward extension I3 of the upper tarsus section and the divisions of the phalanges section, these being located above the joints I8. Also rubber bumpers 21 are interposed between the -upper and lower tarsus sections I, 2, in the recess in the latter, on opposite sides of the spindle or hinge 9. Also a rubber bumper 23 is located between the leg structure and the upper tarsus section I in the rear of the ankle joint.

The leg structure r includes a tibia member which includes upper and lower sections and 3| connected together `by a swivel joint located just above the upper face of the upper tarsus section. The lower lsection 3| extends into the upper tarsus section, or the recess 6 thereof, and is pivoted to the upper tarsus section by a transversely extending ankle joint or hinge 38, this extending crosswise .and infront of the axis of the swivel joint between the sections 30 and 3|. The swivel joint, as here shown, includes a pin 39 extending axially of the sections 30 and 3|, a bushing 40 in the lower section 3| into which the pin extends, the bushing having an annular flange 4| overlying the upper `side of the section 3|, and resilient spring means for applying resistance to the' turning movement of the section 30 relative to the section 3|. The leg structure also includes a frame or tibia member 5| extending on opposite sides of the swivel joint, and a transverse member 42 extending between the sections -30-and 3| Iand lthrusting-against the flan-ge 4| As here shown, the resilient means are spring ar-ms or pron-gs 43 anchored at their lower ends in the lower section 3| on .opposite sides of the pin '3-9 and extendingthrough the ange 4|, into and through alined arcuate slots 44 in the member 42 and the upper section 30, and into holes in a washer 45 anchored tothe section 30, as by a dowel pin 46. The swivelvpin 39 has heads 41 and 48 at its opposite ends for holding it from displacement. During the -swiveling movemen-t of the section 30 relative to the section 3|, obviously the spring prongs 43 will have space to ilex slightly withinlimits d-ue to the arcuate slots 44, and resist the swiveling movement. The swiveling movement takes place Vwhen the weight of the amputee is on the artificial leg and foot, and also the pivotal movement of `the upper tarsus about `the axis 9 takes place while the weight ofthe amputee is on the -articial leg and foot, and the amputee shifts his body laterally in one direction or the other 4while the artificial foot is planted on the ground. The swiveling action permits the leg to change its radial'angle relat'vely inward or outward to the foot during certain movements in walking and other shifts'of the leg, these different relative radial angles being illustrated by the positions designated A,'B and C, in Figure 2.

During the walking cycle, the metatarsal and phalanges sections 3 and 4 shift about their hinged axes while'the amputee is applying his Weight to the artificial foot and lifting the heel off the walking surface while the toeis on the walking surface, the spring 2| applying enough resistance'to make the pivotal movement analasous to that of a natural foot, and also to return the sections to normal position when the amputee lifts the artificial foot from the walking surface. The leg structure in addition to the tibia includes a fibula link 50 which performs its function analogous to that of the bula of a natural leg. The section 3U of the leg structure has a bearing 30| for connection to a knee -brake or lock forming no part of this invention.

This foot structure is particularly advantageous inv that it simulates quite closely the movements of a natural foot during the walking cycle and conditions encountered in normal walking, and permits progressive dorsiexion during walkmg.

What I claim is.'

1. An artificial foot structure, the foot structure includingan upper tarsus'section'and a lower tarsus section hinged together by a forward and rearward extending pivot, a metatarsal section hinged on a transverse axis to the front end of the lower tarsus section, a phalanges section hinged on a transverse axis to the front end of the metatarsal section, the upper tarsus section having a forward extending rigid portion over the metatarsal section, and spring means between the lower tarsus section, the phalangessection and the overhanging-'portion pf the upper tarsus section to oppose flexing of the metatarsal and phalanges sections about their hinged axes.

2. An artificial foot structure, the foot structure including an upper tarsus section and a lower tarsus section hinged together by a forward and rearward extending pivot, a metatarsal section hinged `on va transverse axis to the front end of the lower tarsus section, a phalanges section hinged on a transverse axis to the front end of the metatarsal sectionpthe upper tarsus section having -a forward-extending-'rigid portion over-the metatarsal section, anda 4leaf-spring pressing Vat its opposite endsonthe lowerftarsus'section-and the phalanges `section and fulcrumed'between lits ends onthe under iside of th-e rigid ex-tension'of the upper tarsussection.`

3. An artificial leg andffootstructure, the foot structure includ-ing'an upper ltarsussection and a lower `tarsus se'ctionfhingedltogether .by afor- Award yand rearward exten'dng'rpivot, a'metaitazrsai section hinged on vva transverse axis 'to *the front end of the lower tarsus section, a phalanges'section hin-ged on atransverseaxistotheffront end of the metatarsal'sectiomthe uppertarsus section having a forward ex'temii-r-igl ngi-d Vport-ion over the metatarsai section, and 'spring means between the lower 'tarsus `section. the phalanges section an-d the overhanginglportion'ofthe-'upper tarsussection to oppose flexing-of the'phalang-es section'about its hingedl axis, the'leg struct-ure'including upper-and'lower-sections*swiveled together on Ian upright axisvadjacent-*the upper side of the upper tarsus section, the lower section of the leg structure being connect-ed' to-'the upper tarsus section by a transverse Iank-le 'join-t extending crosswise of the axis ofthe' swve-ledjoin't.

4. An artificial leganti foot-structure; the foot structure including-jan npper-tarsussection Vand a lower tarsussectionihinged-"together'by afforward and rearward extending pivot, a metatarsal section hinged on"ai'fransverse` axis-to the frontend 'of the lowertarsus'section',v aphalanges section hngedon a' transverse -axlsito the *front end of the metatalsalisecti'on,itheupper tarsus section having 'a forward vextending rigid portion over the metatarsal section-anda lleaf spring pressing at its opposite endsonthe lower tarsus section and the phalanges section and ful'crumed between its endsonftheunder side oftheirigid extension of the'upper'tarsussectiony the-leg structure including upper and lower sections'swiv-l eled together'on `an upright a'xi's'a-djacentthe upper side offtheupper tarsus section, thelower section of i the leg structure being "connected "to the upper tarsus Vsection-'bya transverse ankle joint extending crosswise of the axis of theswiveled joint.

5. An artificial foot structuretm-footistructure inc-ludingan upper tarsus vsection and a lower tarsus sectionhinged-togetherby a fortion having a forward extending rigid portion over the metatarsal section, and a leaf spring pressing at its opposite ends on the lower tarsus section and the phalanges section and fulcruined between its ends on the under side of the rigid extension of the upper tarsus section, the leaf spring extending in a general direction in alinernent with the axis of the hinged joint between the upper and lower tarsus sections.

6. An artificial foot structure, the foot structture including an upper tarsus section and a lower tarsus section hinged together by a forward and rearward extending pivot, a metatarsal section hinged on a transverse axis to the front end of the lower tarsus section, a phalanges section hinged on a transverse axis to the front end of the rnetatarsal section, the upper tarsus section having a forward extending rigid portion over the metatarsal section, and a leaf spring pressing at its opposite ends on the lower tarsus section and the phalanges section and fulcrurned between its ends on the under side of the rigid extension of the upper tarsus section, the leaf spring pressing at its rear end on the hinge between the lower tarsus and the metatarsal sections in the Vertical plane of the axis of the hinge joint between the lower tarsus and metatarsal sections, the spring pressing at its front end on the front end portion of the phalanges section and fulcruined between its ends on the under side of the front end of the rigid extension of the upper tarsus section.

7. An artificial foot structure, the foot structure including an upper tarsus section and a lower tarsus section hinged together by a forward and rearward extending pivot, a metatarsal section hinged on a transverse axis to the front end of the lower tarsus section, a phalanges seotion hinged on a transverse axis to the front end of the metatarsal section, the upper tarsus section having a forward extending rigid portion over the metatarsal section, and a leaf spring pressing at its opposite ends on the lower tarsus section and the phalanges section and fulcrumed between its ends on the under side of the rigid extension of the upper tarsus section, the leaf spring pressing at its rear end on the hinge between the lower tarsus and the metatarsal sections in the vertical plane of the axis of the hinge joint between the lower tarsus and metatarsal sections, the spring pressing at its front end on the front end portion of the phalanges section and fulcrurned between its ends on the under side of the front end of the rigid extension of the upper tarsus section, and the spring extending in a general direction in alinement with the hinge joint between the upper and lower tarsus sections.

8. An articial leg and foot structure, the foot structure including an upper tarsus section and a lower tarsus section hinged together by a forward and rearward extending pivot, a metatarsal section hinged on a transverse axis to the front end of the lower tarsus section, a phalanges section hinged on a transverse axis to the front end of the inetatarsal section, the upper tarsus section having a forward extending rigid portion over the metatarsal section, and a leaf spring pressing at its opposite ends on the lower tarsus section and the phalanges section and fulcruined between its ends on the under side of the rigid extension o the upper tarsus section, the leaf spring pressing at its rear end on the hinge between the lower tarsus and the metatarsal sections in the vertical plane of the axis of the hinge joint between the lower tarsus and metatarsai sections, the spring pressing at its front end on the front end portion of the phalanges section and fulcrumed between its ends on the under side of the front end of the rigid extension of ne upper tarsus section, and the spring extending in a general direction in alinement with the hinge joint between the upper and lower tarsus sections, the leg structure including upper and lower sections connected together by a swivel joint adjacent the upper tarsus section, the lower section of the leg structure being pivoted to the upper tarsus by an ankle joint extending transversely of the axis of the swivel joint.

9. An articial foot structure, the foot Structure including an upper tarsus section and a lower tarsus section hinged together by a forward and rearward extending pivot, a metatarsal section hinged on a transverse axis to the front end of the lower tarsus section, a phalanges section hinged on a transverse axis to the iront end oi the metatarsal section, the upper tarsus section having a forward extending rigid portion over the metatarsal section, the phalanges section consisting of right and left divisions pivoted independently of each other at the front end of the rnetatarsal section, and spring means between the lower tarsus section, the divisions of the phalanges section and the overhanging portion of the upper tarsus section to oppose flexing of the metatarsal and the phalanges sections about their hinged axes.

10. An artiiicial foot structure including an upper tarsus and a lower tarsus section hinged together by a forward and rearward extending pivot, a metatarsal section including right and left divisions hinged to the front end of the lower tarsus section, a phalanges section including right and left divisions hinged on a transverse axis to the front ends of the divisions of the metatarsal section respectively, and yielding means between the lower tarsus section and the phalanges divisions to oppose the iiexing of said divisions about their hinged axes.

11. An artificial foot structure including an upper tarsus and a lower tarsus section hinged together by a forward and rearward extending lpivot, a metatarsal section including right and left divisions hinged to the front end of the lower tarsus section, a phalanges section including right and left divisions hinged on a transverse laxis to the front ends of the d'visions of the metatarsal section respectively, yielding means between the lower tarsus section and the phalanges divisions to oppose the exing of said divisions about their hinged axes, said yielding means being common to the divisions of the nietatarsal and phalanges sections.

12. An artiiicial foot structure including an upper tarsus and a lower tarsus section hinged together by a forward and rearward extending pivot, a metatarsal section including right and left divisions hinged to the front end of the lower tarsus section, a phalanges section including right and left divisions hinged on a transverse axis to the front ends of the divisions of the metatarsal section respectively, yielding means between the lower tarsus section and the phalanges divisions to oppose the flexing of said divisions about their hinged axes, said yielding means being common to the divisions of the phalanges section and including a leaf spring extending lengthwise of the metatarsal and phalanges sections and pressing at its ends on the lower tarsus sections at the joint between the lower tarsus section and the rear 7 ends oi" the divisionsy of the` metatarsal section, at its front end on the divisions-of the .phalanges section, and between its ends on the front end of the upper tarsus section;

13'. An artificial' foot structure, the foot structure including an upper tarsus section and a lower tarsus section hinged together by a forward and rearward extending pivot, a metatarsal` section hinged on a transverse axis to the front end of the lower tarsu-s section, a phalangesk section hinged on a transverse axis to the` front end of the metatarsal section, they upper tarsus section having a. forward extending rigid portion over the metatarsal section, spring means between the lower tarsus section, the phalanges section and the overhanging portion of the upper tarsus section toI oppose exing ofthe phalanges sections about their hinged axes, and compressible bumpers between the upper and lower tarsus sections on opposite sides of the forward and rearward extending axis of the hinged joint connecting them.

14. An artificial foot structure including an upper tarsus and a lower tarsus section hinged together by a forward and rearward extending pivot, a metatarsai section including right and lefty divisions hinged to the front end of the lower tarsus section, a phalanges section including right and left divisions,v hinged on a transverse axis to the front ends of the divisions. of the metatarsal section respectively, yielding means between the lower tarsus section and the phalanges divisions to oppose the flexingv of said divisions abouttheir hinged axes, said yielding means being common to the divisions of t i e metatarsal and phalanges sections and including a leaf spring extending lengthwise or the metatarsal and phalanges sections and pressing at its ends on the lower tarsus sections at the joint between the lower tarsus section and the rear ends of the divisions of the metatarsal section, at its front` end on the divisions of the phalanges section, and between its ends on the front end of the Lipper tarsus section, and compressible bumpers between the upper and lower tarsus sections, on opposite sides of the forward and rearward extending axis of the hinged joint connecting them, and compressible bumpers between the joint between the divisions of the inetatarsal and phalanges sections, and the front end of the upper tarsus section.

JOHN G. CATRANIS.

No references cited. 

